# `Spacer`: Declarative Inter-Block Spacing Policies

```{py:currentmodule} myform.Spacer
```

A `Spacer` is a small predicate object describing when a pair of adjacent block nodes deserves
non-default vertical spacing: it can match on node types, rendered texts, a custom condition
function, or any combination of the three. `Renderer.render_block_spacing()` consults the
registered spacers in order and applies the first match.

```{eval-rst}
.. automodule:: myform.Spacer
   :members:
```